The subject matter disclosed herein relates to rotating and stationary components of turbomachinery and, more particularly, to a blade and disk dovetail design for turbine systems.
Certain turbine rotor disks include a plurality of circumferentially spaced dovetail slots about the outer periphery of the disk. Each of the dovetail slots receives a blade formed with an airfoil portion and a blade dovetail having a male portion complementary to the female portion of the dovetail slots. The blade dovetail is received by the dovetail slot in an axial direction.
During operation of the turbine, movement of certain components and flow of compressed air and hot gas through the turbine can cause vibration in the turbine system. For example, the vibration of rotating blades can be driven by air or gas flowing through adjacent static vanes. Specifically, during operation of the turbine system, driving frequencies are caused by pulses formed as fluid passes through blades in the compressor or turbine. It is desirable for blades to be designed such that their fundamental natural frequencies either avoid the driving frequencies or can withstand the vibration caused by them, otherwise wear, high cycle fatigue, and other damage to components can occur. Repair and/or replacement of components due to vibration induced fatigue can be costly and time consuming